1. Field of the Invention
This invention relates to the jet tangling of moving textile strands and especially relates to an apparatus for the continuous jet tangling of filamentary yarn on the run.
2. Description of the Prior Art
In the processing of synthetic continuous filaments, various treatments have been devised to produce so-called texturized continuous filament yarns which are bulky and have wool-like properties. It is well known in the textile industry to obtain these effects by treatment of running yarns with fluid streams. The fluid processes permit effective treatment at high linear yarn speeds.
Breen U.S. Pat. No. 2,783,609, for example, discloses a technique for improving the bulk of continuous filament yarns rendering them light in weight and causing them to have a bulk and surface texture comparable to yarns spun from natural staple fibers. This technique involves exposing a filamentary material to a rapidly moving turbulent fluid, thereby inducing formation of a multitude of filament loops arranged at random intervals along the lengths of the individual filaments. Yarn produced by stuffer crimping has similar properties and qualities; the Breen jet produces loops in the yarn filaments in order to provide a bulked continuous filament yarn.
Such yarns, however, are sharply distinguishable from so-called compact yarns, which are also produced by running the yarn through a fluid jet. This involves fluid treatment of textile strands to make them more compact and to improve their structural integrity without twisting, as in U.S. Pat. No. 3,364,537 (Bunting and Nelson), 3,083,528 (Dalstrom & West), and 3,426,406 (McCutchen), for example. However, they rely upon relatively uncontrolled or random fluid turbulences, as in whipping the component filaments of a multifilament strand about the strand axis, for example.
Stanley U.S. Pat No. 3,279,025 discloses a stuffer crimper in which the exit from the yarn crimping chamber is substantially unrestricted, and which operates in self-balancing manner, wherein the yarn speed is kept substantially constant both in crimping and winding. Although we have endeavored to impart cohesiveness to the bulky yarn produced by such stuffer crimpers, by the use of jet tanglers, difficulties have been encountered due to the aspirating effect of the jet. In many cases, this effect tended to strip considerable quantities of yarn from the stuffer crimper chamber, thus upsetting its inherent balance and producing non-uniform yarn. To overcome this, it has been found necessary to increase the yarn take-up tension to minimize the aspiration effect, thus reducing the available degree of entanglement.